Distributor for internal combustion engines and controls therefor



Aug. 10, 1965 MOLLER 3,199,500

DISTRIBUTOR FOR INTERNAL COMBUSTION ENGINES AND CONTROLS THEREFOR Filed May 21, 1963 2 Sheets-Sheet 1 H. MULLER Aug. 10, 1965 DISTRIBUTOR FOR INTERNAL COMBUSTION ENGINES AND CONTROLS THEREFOR 2 Sheets-Sheet 2- Filed May 21, 1965 INVENTOR file/ 05/15.!

United States Patent 3,199,590 DISTRIBUTGR FGR INTERNAL COMBUSTIGN ENGINES AND CQNTRULS THEREFOR Heinz Miiller, Stuttgart, Germany, assignor to Robert Bosch G.m.b.H., Stuttgart, Germany Filed May 21, 1963, Ser. No. 281,894 Claims priority, application Germany, May 25, 1962, R 49,325 4 Claims. (Cl. 123-1465) The present invention relates to internal combustion engines.

More particularly, the present invention relates to distributors for internal combustion engines and to control structure for such distributors.

As is well known, the basic function of a distributor of internal combustion engine is not only to distribute the spark to the various cylinders according to a predetermined timing sequence, but also to time the distribution in such a way that the spark will be provided at a predetermined instant with relation to the position of the piston in a particular cylinder. For example, it is known that the rotary cam of the distributor can be adjusted by a centrifugal adjusting structure according to the engine speed so as to retard or advance the timing and thus improve the operation of the engine.

Although structures for adjusting the timing of distributors are well known, the best possible adjustment thereof without any delay has not yet been attained. More specifically, it is highly desirable to be able to adjust the timing of the distributor according to the operating requirements of the engine, and under certain circumstances, as when there is a sudden change in the load on the engine, it is not yet possible with known structures to provide without delay an adjustment of the timing in response to such a sudden change in load.

It is accordingly a primary object of the present invention to provide for a distributor a structure which will automatically adjust the timing of the distributor to adapt the operation to different operating requirements without delay even in the case where a sudden change in load on the engine is encountered.

It is furthermore an object of the present invention to provide a structure which will accomplish this result in a simple, uncomplicated manner with elements which operate reliably and which do not require a large amount of space.

More specifically, it is an object of the present invention to provide a structure which will automatically retard the timing of the distributor as the accelerator lever or pedal is moved by the operator beyond an intermediate position of the accelerator lever toward the openthrottle end position thereof.

With these objects in view the invention includes a distributor which has a rotary cam means adapted to be driven by the engine, and interrupter switch means actuated by the rotary cam means, a turnable interrupter plate carrying the interrupter switch means, and a centrifugal means operatively connected to the rotary cam means for adjusting the latter to adjust the timing of the distrbutor according to the engine speed. The accelerator lever or pedal is operatively connected through a first transmission means to a throttle valve for turning the latter between a substantially closed position and a substantially fully open position during turning of the accelerator lever between an idling end position and an open-throttle end position, respectively. In accordance with the present invention a second transmission means is operatively connected to the first transmission means and to the rotary interrupter plate for turning the latter in response to transmission of motion by said first transmission means from said accelerator lever to said throttle valve, but the second transmission means provides no turning of the interrupter plate during turning of the accelerator lever from the idling end position thereof to a predetermined intermediate position, and the second transmission means automatically turns the interrupter plate in a direction which retards the timing of the distributor when the accelerator lever is turned beyond this intermediate position thereof toward the open-throttle end position thereof.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with addition-a1 objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIG. 1 is a partly sectional, partly diagrammatic elevation of a distributor;

FIG. 2 shows in a plan view the distributor of FIG. 1 with the cover and distributor plate thereof removed, FIG. 2 also showing in a partly diagrammatic manner the connection between the distributor and the throttle valve of the carburetor, FIG 2 also illustrating diagrammatically the connection of the accelerator lever to the throttle valve; and

FIG. 3 shows another embodiment of a structure according to the invention, the distributor of FIG. 3 being illustrated with its carburetor and distributor plate removed and FIG. 3 also showing diagrammatically the connection of the accelerator lever to the throttle valve.

Referring first to FIG. 2, there is shown therein a distributor which includes the housing 10 and the turnable interrupter plate 11 which is supported for turning movement by the distributor housing 10. The turnable interrupter plate carries a switch means which includes the interrupter lever 12 which carries a movable contact 13 which turns together with the interrupter lever 12 as well as a projection 14 adapted to be engaged by the rotary cam means 18, and a spring 15 operates in a known way on the lever 12 to urge the latter to turn with respect to the plate 11 in a counterclockwise direction, as viewed in FIG. 2. A contact carrier 16 is fixedly carried by the interrupter plate 11 and carries the stationary contact 17 of the interrupter switch means. The cam means 18 is rotated in a clockwise direction, as shown by the arrow of FIG. 2, through a drive from the engine, as is Well known in the art.

Referring to FIG. 1, it will be seen that the rotary cam means 18 is carried by the engine-driven shaft 42 which is the main drive shaft of the distributor while being capable of being angularly adjusted relative to the shaft 42 so that the cam 18 turns with the shaft 42 but can be angularly adjusted relative thereto for regulating the timing of the distributor. A centrifugal means is operatively connected to the cam means 18 for angularly adjusting the latter relative to the shaft 42, and this centrifugal means includes the freely turnable weights 41 which turn with the shaft 42 and which will assume angular positions according to the speed of rotation of the shaft 42, these weights being operatively connected in a known way to the cam 18 for angularly adjusting the latter so that in this Way the timing of the distributor is automatic-ally regulated according to the engine speed.

The drawing shows diagrammatically in FIG. 2 an accelerator lever 43 which is illustrated in its idling end position. This lever .is turnable in a counterclockwise direction, as viewed in FIG. 2, to an opposite openthrottle end position, and in an engine-driven vehicle the accelerator lever 43 will be in the form of a pedal. As is diagrammatically indicated in FIG. 2 the accelerator lever 43 is operatively connected to a throttle valve 25 located in a duct 26 of the carburetor through a motion transmitting means winch includes the lever 2'7 which is connected to the valve 25 so as to turn the latter when the lever 27 turns. The duct 26 is of course the suction conduit of the carburetor through which the fuel-air mixture enter into the engine.

In accordance with the present invention, a second transmission means interconnects the first transmission means, which extends between the lever 43 and the throttle valve 25, with interrupter plate 11 for turning the latter automatically in a manner described below. Thus, the second transmission means includes a Bowden cable 24 having an outer sheath through which extends a wire 23 fixed at one end to the lever 27 and at its opposite end to a lever 22 of the second motion transmitt-ing means, this lever 22 being turnably carried by the distributor housing in for turning movement about an axis parallel to the axis of the cam 18. The interrupter plate ll carries a disc 19 which is fixed to the interrupter plate 1-1, and the disc19 and lever 22 form a pair of elements of the second motion transmission means which are interconnected by a pin-an-slot connection 29, 21. This pin-and-slot connection includes the slot 25 which is formed in the disc 19 and a pin 21 which is fixed to the lever 22 and which extends into the slot 2%).

It will be noted that the slot 20 has a particular curvature and is provided with a pair of legs which extend angularly with respect to each other. The right leg of the slot 2i), as viewed in FIG. 2, in which the pin 21 is located in the position of the parts shown in FIG. 2, extends along a circle whose center is in the turning axis of the lever 22, so that during the initial turning of the lever 22 in a clockwise direction, as viewed in FIG. 2, from the position thereof shown in FIG. 2 the pin 2% will simply move along the right leg of the slot 20 without providing any turning of the interrupter plate i=1. However, when the pin 21 moves beyond the right leg of the slot 20 into the left leg thereof, as viewed in FIG. 2, it is clear that the direction in which this left leg extends will provide turning of the interrupter plate 11 in response to continued turning of the lever 22 in a clockwise direction, .as viewed in FIG. 2. It is clear that the turning of the interrupter plate 11 resulting from turningo'f the lever 22 in a clockwise direction, as viewed in FIG. 2, beyond the point where the pin 21 is located in the right leg of the slot 20 as viewed in FIG. 2, will provide turning of the interrupter plate llll in the same direction as the cam 18, so that the result is that the timing is retarded in this way.

When the accelerator lever 43 is in the illustrated idling end position thereof shown in FIG. 2 the valve 25 is substantially closed, and the lever 43 will act through the first transmission means which includes the lever 27 on the valve 25 for displacing the latter fully to its open position when the lever 43 reaches its open-throttle end position. During this turning of the lever 43 from its idling end position toward its open-throttle end position the lever 27 and the valve 25 will turn in a counterclockwise direction, as viewed in FIG. 2, and the wire 23 of the Bowden cable will therefore be advanced to the left as viewed in FIG. 2, resulting in clockwise turning of the lever 22, as viewed in FIG. 2. Therefore, until the lever 43 reaches .a predetermined intermediate position between its idling end position and its open-throttle end position, the pin 21 will simply advance along the right leg of the slot 2% without providing any turning of the interrupter plate 11. However, when the lever 43 moves beyond this intermediate position toward the open-throttle end position thereof, the pin 21 will enter into the left-leg of the slot 20, as viewed in FIG. 2, and will provide automatic turning of the interrupter plate 11 so as to retard the timing of the distributor, and in this way the combination 'of centrifugal adjustment of the cam 18 according to the engine speed and adjusting of the plate 11 according to the position of the lever t3 will provide automatic, undelayed regulation of the timing of the distributor according to any change in the operating requirements of the engine, even if this change should be a sudden change in the load on the engine. Of course, as long as the accelerator lever 43 is between its idling end position and the above-mentioned intermediate position thereof, the pin 21 is located in the right leg of the slot 21 as viewed in FIG. 2, and thus at this time the adjustment of the timing is provided only by the centrifugal means which acts on the cam 18 in the manner described above.

Thus, by the conventional operation of the accelerator lever or pedal 43, there will be provided with the structure of the invention, in addition to the centrifugal regulation of the timing of the distributor according to the engine speed, a regulation of the timing according to the load whenever the throttle valve is between the above-mentioned intermediate position and the openthrottle end position thereof, and of course the nature of the adjustment will depend upon the location of the accelerator lever &3 and the direction in which it is displaced.

The embodiment of the invention which is illustrated in FIG. 3 operates according to the same principle.

Referring to FIG. 3, it will be seen that there is shown therein a distributor housing 39 supporting for turnable movement the interrupter plate 31 which carries an interrupter switch means identical with that of FIG. 2 and actuated by the identical cam means which is also centrifugally regulated in the manner described above in connection with FIG. 1.

FIG. 3 also shows diagrammatically the accelerator lever 43 which is also connected through a transmission means to the throttle valve 4t} located in the suction conduit 35 of the carburetor. This first transmission means includes a lever 38 which is fixed to the rotary shaft 39 which carries the butterfly valve 40.

The second transmission means of the invention in the embodiment of FIG. 3 includes a portion of the lever 38 which is formed with the slot 37. In addition, this second transmission means of the embodiment of FIG. 3 includes a lever 34 turnably carried by the conduit 35 and having a pin-and-slot connection with the lever portion of the lever 38 which forms part of the second trans mission means for transmitting movement from the first transmission means to the interrupter plate 31. This pinand-slot connection includes the pin 36 which is fixed to the lever 34 for turning movement therewith and which extends into the slot 37. It will be noted that this slot 37 has a configuration similar to the slot 20. The right leg of the slot 37, as viewed in FIG. 3, extends along a circle whose center is located in the axis of turning of the valve 40 so that during initial turning of the lever 38 in a clockwise direction, as viewed in FIG. 3, the right leg of the slot 37 will become displaced relative to the pin 36, also in a clockwise direction as viewed in FIG. 3, but no turning of the lever 34 will result. It is only when the left leg of the slot 37 reaches the slot 36 that the lever 3 will be turned. The second motion transmitting means of FIG. 3 also includes a Bowden cable, and the sheath of this cable covers a wire 32 the ends of which are respectively fixed to the lever 34 and the interrupter plate 31, a clamping screw 33 being provided for clamping the end of the wire 32 of the Bowden cable to the interrupter plate 31.

Thus, with the embodiment of FIG. 3 during the initial turning of the lever 4-3 from its illustrated idling end position in a ciockise direction toward the opposite openthrottle end position thereof, only the right leg of the slot 37 will become displaced relative to the pin 36 as valve 44 moves from its substantially closed position towards its substantially fully open position, and thus during this initial deflection of the accelerator lever 43 no turning of the interrupter plate 31 will be provided. However, as soon as the left leg of the slot 37, as viewed in FIG. 3, reaches the pin 36, the continued turning of the lever 38 will result in clockwise turning of the lever 34, as viewed in FIG. 3, with the result that the wire 32 will again be pulled to the left, as viewed in FIG. 3, and thus the interrupter plate 31 will be turned in the same direction as the cam 18, which is a clockwise direction, as viewed in FIG. 3, and thus the timing of the distributor will again be retarded. Thus, with the embodiment of FIG. 3 also as long as the lever 43 is between its idling end position and a predetermined intermediate position there will be no turning of the interrupter plate 31 and the adjustment of the timing will result solely from the centrifugal adjustment of the cam means of the distributor, while the additional adjustment according to the position of the lever 43 will take place whenever the lever 43 is between its intermediate position and the open-throttle end position thereof, in the same way as described above in connection with FIG. 2.

It will be understood that each of the elements described above or two or more together, may also find a useful application in other types of distributors differing from the types described above.

While the invention has been illustrated and described as embodied in distributor and controls therefor, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed and desired to be secured by Letters Patent is:

1. For use with an internal combustion engine, in combination, a distributor including rotary cam means adapted to be driven by the internal combustion engine, interupter switch means actuated by said rotary cam means, centrifugal means operatively connected to said cam means for adjusting the latter according to the engine speed so as to adjust the timing of the distributor, and a turnable interrupter plate carrying said switch means for adjusting the latter relative to said cam means so as to further adjust the timing of the distributor; a throttle valve; an accelerator lever; first motion transmitting means operatively connected to and extending between said accelerator lever and throttle valve, said accelerator lever having an idling end position where said first transmission means places said throttle valve in a substantially closed position and said accelerator lever having an opposed open-throttle end position where said first transmission means places said throttle valve in a substantially fully open position; and second transmission means operatively connected to said first transmission means and said interrupter plate for adjusting the latter according to the position of said throttle valve, said second transmission means maintaining said interrupter plate stationary during movement of said lever from said idling end position thereof to an intermediate position between said idling and open-throttle end positions of said lever and said second transmission means transmitting movement of said first transmission means to said plate for turning the latter in a direction which retards the timing of the distributor during movement of said accelerator lever beyond said intermediate position thereof toward said open-throttle end position thereof, said second transmission means including a pair of motion transmitting elements and a pin-and-slot connection therebetween, the slot of said pin-and-slot connection having a curvature which prevents transmission of motion by said second motion transmitting means from said first motion transmitting means to said interrupter plate during turning of said accelerator lever between said idling end position and said intermediate position thereof and which provides turning of said interrupter plate when said accelerator lever is moved within the range of turning thereof located between said intermediate position and said open-throttle end position thereof, said distributor including a distributor housing, said pair of motion transmitting elements of said second motion transmitting means including a lever member turnably connected to said housing and a second member fixed to said interrupter plate, one of said members carrying the pin of said pin-and-slot connection and the other of said members carrying the slot of said pin-and-slot connection.

2. The combination of claim 1 and wherein the member which is fixed to said plate is formed with said slot and said lever which is connected to said distributor housing fixedly carries the pin of said pin-and-slot connection, said pin being located in said slot.

3. For use with an internal combustion engine, in com bination, a distributor including a distributor housing, rotary cam means adapted to be driven by the engine, a turnable interrupter plate coaxial with said cam means and supported by said housing for turning movement, interrupter switch means carried by said interrupter plate and actuated by said rotary cam means, and centrifugal means operatively connected to said rotary cam means for automatically adjusting the latter according to the engine speed for adjusting the timing of the distributor; a first adjusting member carried by said interrupter plate and formed with a slot; at second adjusting member turnably connected to said housing and carrying a pin which is located in said slot; a Bowden cable connected to said second adjusting member for turning the latter so as to move the pin relative to the slot; a throttle lever connected to an end of said Bowden cable distant from said second adjusting member; a throttle valve connected to said trottle lever to be turned thereby; and an accelerator lever operatively connected to said throttle lever for turning the latter and said throttle valve therewith, said accelerator lever being turnable from an idling end position to an open-throttle end position during which said throttling lever turns said valve from a substantially closed to a substantially fully open position, respectively, and said Bowden cable transmitting turning of said throttle lever to said second adjusting member for moving said pin relative to said slot of said first adjusting member, the curvature of said slot maintaining said interrupter plate stationary during movement of said accelerator lever from said idling end position thereof to a predetermined intermediate position between said idling end position and said open-throttle end position, and the curvature of said slot providing turning of said interrupter plate in a direction which retards the timing of the distributor during movement of said accelerator lever beyond said intermediate position thereof toward said open-throttle end position thereof.

4. For use with an internal combustion engine, in combination, a distributor including a distributor housing, rotary cam means adapted to be driven by the engine, a turnable interrupter plate coaxial with said cam means and supported by said housing for turning movement, interrupter switch means carried by said interrupter plate and actuated by said cam means, and centrifugal means operatively connected to said rotary cam means for adjusting the latter to adjusting the timing of the distributor; a Bowden cable connected at one end to said interrupter plate; first lever means connected to the opposite end of said Bowden cable; second lever means having a pin-andslot connection with said first lever means; a thottle valve connected to said second lever means to be turned thereby; and an accelerator lever operatively connected to said second lever means for turning the latter, said accelerator lever being turnable between an idling end position and an open-throttle end position and acting through said second lever means on said throttle valve to turn the latter from a substantially closed to a substantially fully open position during turning of said accelerator lever from said idling end position thereof to said open-thottle end pasition thereof, the slot of said pin-and-slot connection having a curvature which provides no turning of said plate during turning of said accelerator lever from said idling end position thereof to a predetermined intermediate position between said idlingend position and said open-throttle end position thereof, and the curvature of said slot providing through said first lever means and Bowden cable a turning of said interrupter plate in a direction which retards the timing of said distributor during turning of said accelerator lever beyond said intermediate position thereof toward said open-throttle end position thereof, said second lever means being formed with said slot and said first lever means carrying a pin which is located in said slot to form said pin-and-slot connection. 7

References Cited by the Examiner UNITED STATES PATENTS 1,541,052 6/25 Hunt 12399 1,611,054 12/26 Mayoral l2398 2,688,055 8/54 Schneider et al. 123-1465 RICHARD B. WILKINSON, Primary Examiner. 

1. FOR USE WITH AN INTERNAL COMBUSTION ENGINE, IN COMBINATION, A DISTRIBUTOR INCLUDING ROTARY CAM MEANS ADAPTED TO BE DRIVEN BY THE INTERNAL COMBUSTION ENGINE, INTERRUPTER SWITCH MEANS ACTUATED BY SAID ROTARY CAM MEANS, CENTRIFUGAL MEANS OPERATIVELY CONNECTED TO SAID CAM MEANS FOR ADJUSTING THE LATTER ACCORDING TO THE ENGINE SPEED SO AS TO ADJUST THE TIMING OF THE DISTRIBUTOR, AND A TURNABLE INTERRUPTER PLATE CARRYING SAID SWITCH MEANS FOR ADJUSTING THE LATTER RELATIVE TO SAID CAM MEANS SO AS TO FURTHER ADJUST THE TIMING OF THE DISTRIBUTOR; A THROTTLE VALVE; AN ACCELERATOR LEVER; FIRST MOTION TRANSMITTING MEANS OPERATIVELY CONECTED TO AND EXTENDING BETWEEN SAID ACCELERATOR LEVER AND THROTTLE VALVE, SAID ACCELERATOR LEVER HAVING AN IDLING END POSITION WHERE SAID FIRST TRANSMISSION MEANS PLACES SAID THROTTLE VALVE IN A SUBSTANTIALLY CLOSED POSITION AND SAID ACCELERATOR LEVER HAVING AN OPPOSED OPEN-THROTTLE END POSITION WHERE SAID FIRST TRANSMISSION MEANS PLACES SAID THROTTLE VALVE IN A SUBSTANTIALLY FULLY OPEN POSITION; AND SECOND TRANSMISSION MEANS OPERATIVELY CONNECTED TO SAID FIRST TRANSISSION MEANS AND SAID INTERRUPER PLATE FOR ADJUSTING THE LATTER ACCORDING TO THE POSITION OF SAID THROTTLE VALVE, SAID SECONG TRANSMISSION MEANS MAINTAINING SAID INTERRUPTER PLATE STATIONARY DURING MOVEMENT OF SAID LEVER FROM SAID IDLING END POSITION THEREOF TO AN INTERMEDIATE POSITION BETWEEN SAID IDLING AND OPEN-THROTTLE END POSITIONS OF SAID LEVER AND SAID SECOND TRANSMISSION MEANS TRANSMITTING MOVEMENT OF SAID FIRST TRANSMISSION MEANS TO SAID PLATE FOR TURNING THE LATTER IN A DIRECTION WHICH RETARDS THE TIMING OF THE DISTRIBUTOR DURING MOVEMENT OF SAID ACCELER- 